Field of the Invention
The present invention relates to a display apparatus and a control method thereof.
Description of the Related Art
In recent years, a high dynamic range (HDR) display that allows a lifelike display image (an image displayed on a screen) by using multi-bit image data is performed.
As one of methods for recording HDR image data (multi-bit image data) having a wide dynamic range and a wide color gamut, there is a method in which the HDR image data is divided into base image data and difference data, and the base image data and the difference data are recorded (Japanese Patent Application Laid-open No. 2011-193511). That is, as one of data formats of the HDR image data, there is a format that uses the base image data and the difference data. The base image data is low-bit image data obtained by performing gradation compression on the HDR image data. The difference data is, e.g., data representing a difference in brightness value (gradation value) between the base image data and the HDR image data.
When such a data format is used, it becomes possible to perform image display in both of a display apparatus that can execute the HDR display and a display apparatus that cannot execute the HDR display. Specifically, in the display apparatus that can execute the HDR display, it is possible to restore the HDR image data from the base image data and the difference data and display the HDR image data. In the display apparatus that cannot execute the HDR display, it is possible to display the base image data.
In addition, when the above-described data format is used, it is possible to reduce a signal band between an output apparatus (an apparatus that outputs image data) and the display apparatus. Specifically, there is proposed a technology in which the output apparatus outputs the base image data and the difference data, and the display apparatus restores the HDR image data from the base image data and the difference data (Japanese Patent Application Laid-open No. 2007-121375). By dividing the HDR image data into the base image and difference information and outputting the base image and the difference information, it is possible to reduce the signal band as compared with the case where the HDR image data is outputted.
However, in a conventional display apparatus, multi-bit HDR image data is processed in order to obtain a display image having a wide dynamic range and a wide color gamut. Accordingly, a processing load and a circuit size are increased.